1. Field of the Invention
The present invention relates to gaming machines and more particularly to methods of verifying the integrity of remote gaming machines.
2. Description of the Related Art
A common problem for ensuring that distributed computing system continues to operate in a correct, secure and stable fashion arises due to the ease with which individual computing devices (e.g., desk top work stations, portable client devices, server platforms, etc.) can have configuration settings changed, hardware components added or removed and application software components installed or uninstalled.
The gaming industry, in particular, must conform to extensive regulation in multiple jurisdictions where ensuring that computing devices that are deployed as part of a gaming system all conform exactly to pre approved hardware and software configuration. As the industry moves from systems largely or entirely based on custom developed hardware and software components towards the inclusion of more sophisticated commercial off the shelf products, the difficulty of monitoring and controlling the configuration of those systems will greatly increase even as the need for such monitoring becomes more severe.
To satisfy security and regulatory requirements in a gaming environment, a gaming machine must demonstrate sufficient safeguards that prevent an operator or player of the gaming machine from manipulating the hardware and software in a manner that gives them an unfair and some cases an illegal advantage. The gaming machine typically includes a means to determine if the code it will execute is valid and whether the code has been tampered with. If the code is not valid or has been tampered with, the gaming machine is believed to be compromised and game play is stopped or suspended. This can also trigger additional security operations.
Gaming safeguards come in a variety of forms. Gaming machines may include security measures that detect physical intrusion. For example, gaming machines may include a security system that monitors security switches attached to access doors of the gaming machine. Gaming machines may also utilize evidence tape to physical detect tampering between visits by a gaming regulator. The evidence tape is laid across a newly installed memory device, and if broken indicates that that the memory device has been tampered with.
Gaming machines may also include security measures that detect electronic intrusion. If the code is stored on a read only memory device such as an EPROM, a unique signature can be determined for the code stored on the EPROM using a method such as a CRC. Then, prior to installing the EPROM on the gaming machine, the unique signature can be compared with an approved signature.
On less secure memory subsystems, trusted memory devices may be used to ensure the authenticity of the code. Trusted memory devices and controlling circuitry are typically designed to not allow modification of the code and data stored in the memory device while the memory device is installed in the gaming machine. The code and data stored in these devices may include authentication algorithms, random number generators, authentication keys, operating system kernels, etc. The purpose of these trusted memory devices is to provide gaming regulatory authorities a root trusted authority within the computing environment of the slot machine that can be tracked and verified as original. This may be accomplished via removal of the trusted memory device from the slot machine computer and verification of the secure memory device contents is a separate third party verification device. Once the trusted memory device is verified as authentic, and based on the approval algorithms contained in the trusted device, the gaming machine is allowed to verify the authenticity of additional code and data that may be located in the gaming computer assembly such as code and data stored on hard disk drives.
While these measures work well, there is desired improved systems and techniques for ensuring that a gaming device continues to operate in a correct, secure and stable fashion.